The use of quadrature demodulator circuits to assist in data detection is well known in the data communications art. Quadrature demodulators typically employ delay elements whose frequency of operation must be aligned with the input signal (i.e., carrier signal) center frequency in order to avoid distortion at the demodulator output. Since this alignment has heretofore been a manual operation requiring human interaction, the process may be fairly characterized as highly subjective and prone to error.
Another concern with manual demodulator alignment procedures is the inability to maintain their integrity over long periods of operation. Factors such as mechanical stress and thermal cycling tend to degrade a demodulator's performance over time. Consequently, periodic realignments, while undesirable and costly, are nonetheless necessary to insure proper performance.
Based on the foregoing, a need exists for a demodulator alignment method and/or apparatus that continuously aligns a demodulator circuit thereby avoiding the shortcomings of the prior art.